The present invention relates generally to brake control apparatus on locomotives, and more particularly to two operator brake valve handle stations in the cab of a locomotive that are operable exclusively of one another.
The cab of locomotive generally has two brake valve handle stations providing service and emergency braking. One of the handle stations is an xe2x80x9cindependentxe2x80x9d handle and the other is an xe2x80x9cautomaticxe2x80x9d handle. With the independent handle, an operator/engineer applies and releases brakes of the locomotive only. With the automatic handle, the operator applies and releases the brakes not only of the locomotive but also of each car of a train of cars connected to the locomotive. Each handle directly operates a valve located at each station, the valve being effective to operate the brakes using pressurized air contained in main reservoirs located on the locomotive.
In addition, each handle station provides analogue encoded signals to computers for braking, such signals indicating the amount of brake cylinder pressure called for by the brake handle position, as manually operated by the operator/engineer.
The present invention is directed to providing a locomotive cab with two brake handle stations and one brake control computer. The computer is connected and programmed to received coded input brake signals from both stations but in a manner that permits only one station to function at a time as the xe2x80x9cactivexe2x80x9d station while the other station remains dormant or inactive. The computer processes signal selection of the active station based upon manual handle position selection by the operator/engineer. As an option, the inactive station can report emergency requests to the computer, thereby allowing emergency action to be initiated from either station.
To change from one operator station to the other the software of the computer requires the locomotive to be stationary and the brakes of the locomotive and cars to be applied at full service or beyond. To prevent an accidental undesirable release of the brakes at switch-over or transition from a currently active to a currently inactive state the computer requires both stations to be in a full brake service position.
The brake cylinders of the locomotive and cars must also be in full service, as bailoff of the locomotive brakes invalidates the change over procedure. (Bailoff refers to an automatic release of the locomotive brake to care for slack between cars of the train).
The software of the computer interlocks handle selector inputs to the computer so that transition to a valid state can take place when the train is stopped, with brake cylinder pressure being at full service or beyond and both brake valve handles being at full service position or beyond. This interlock insures that the change over always coincides with an operator request.
It is therefore a primary objective of the invention to provide dual brake operator stations in the cab of a locomotive, with control of train brakes being limited to only one station.
It is a Further objective of the invention to insure that change over between brake handle stations occurs in accordance with operator instructions.
Yet another objective of the invention is to interface two brake handle selector switches with a single computer in a locomotive cab.
A further objective is to insure disabling of an inactive handle station in a locomotive cab having two brake handle stations such that an active handle unit will function as it the cab has only a single brake valve handle and operator station.
Another objective of the invention is to change operating modes in a locomotive cab as one unit. For example, if an operator changes from LEAD/CUT-in to LEAD/CUT-out at one station and then changes from ore station to the other, the cab will be LEAD/CUT-out at the other station as well.